python-pillow/Pillow
1
1
Fork 0
mirror of https://github.com/python-pillow/Pillow.git synced 2025-12-03 16:24:24 +03:00
Code Issues Packages Projects Releases Wiki Activity

Read all non-zero transparency from mode 1 PNG images as 255 (#9282)

Browse Source
This commit is contained in:
Hugo van Kemenade 2025-11-30 22:20:38 +02:00 committed by GitHub
commit 2150f088ed
No known key found for this signature in database
GPG Key ID: B5690EEEBB952194
2 changed files with 12 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
Tests/test_file_png.py
View File

@ -338,6 +338,15 @@ class TestFilePng:
assert colors is not None
assert colors[0][0] == num_transparent
def test_save_1_transparency(self, tmp_path: Path) -> None:
out = tmp_path / "temp.png"
im = Image.new("1", (1, 1), 1)
im.save(out, transparency=1)
with Image.open(out) as reloaded:
assert reloaded.info["transparency"] == 255
def test_save_rgb_single_transparency(self, tmp_path: Path) -> None:
in_file = "Tests/images/caption_6_33_22.png"
with Image.open(in_file) as im:

4
src/PIL/PngImagePlugin.py
View File

@ -509,7 +509,9 @@ class PngStream(ChunkStream):
# otherwise, we have a byte string with one alpha value
# for each palette entry
self.im_info["transparency"] = s
elif self.im_mode in ("1", "L", "I;16"):
elif self.im_mode == "1":
self.im_info["transparency"] = 255 if i16(s) else 0
elif self.im_mode in ("L", "I;16"):
self.im_info["transparency"] = i16(s)
elif self.im_mode == "RGB":
self.im_info["transparency"] = i16(s), i16(s, 2), i16(s, 4)